Natural Extract Containing Xanthohumol, and Method for the Production Thereof Products Produced Therefrom

ABSTRACT

The invention relates to a method for producing an extract containing xanthohumol (XN), which is obtained from toasted cereal products, cereal malt, coffee or cocoa. The XN-content in said extract is in the region of 10 mg/kg-2 g/kg xanthohumol. The use of XN-toasted extracts enables the XN-content of foodstuffs and pharmaceutical products to be increased in a natural manner.

TECHNICAL FIELD

The present invention relates to a method for producing a roastedextract from cereals, cereal malt or coffee comprising xanthohumol (XN)and a hop extract comprising xanthohumol as well as its use for theproduction of beverages and/or food products.

BACKGROUND ART

Hop is used as raw material for the production of beer. Hop provides thebitter impression of beer but also an elongated shelf life due to itsantibacterial effect.

The most important compounds contained in hop are, besides the bitteracids (e.g. α-acids), essential oils, tannins and polyphenols.

Xanthohumol, a prenylflavonoid (polyphenol) of hop which occurs in thelupulin glands of the hop cones has a plurality of positive effects.Beside the antiviral and the anti-oestrogenic and anti-inflammatoryeffect, a cancer-chemo preventive activity of XN is also discussed whichactivity is currently under investigation in animal experiments. Thecontent of xanthohumol in hops varies depending on the hop varietybetween 0.1 and 1%. The hop varieties having a high content ofxanthohumol usually comprise a high portion of bitter substances.

Hop products may be divided in raw hops, hop pellets and hop extracts.Since xanthohumol occurs only in the lupulin glands of the hop cone, hoppellets exhibit a high content of XN corresponding to the accumulationof α-acids. Hop extracts may be obtained by extraction with CO₂ and/orethanol. Whereas CO₂ extract hardly comprises any xanthohumol XN isextracted almost completely during the ethanol extraction. Recently, XNenriched products are produced by a combination of both extractionmethods. Depending on the production method XN contents of between 8 and99% are achieved. The production of hop extracts enriched with XN anddrinks comprising XN is described e.g. in the patents DE 19939350, DE10256031, DE 10240065 and EP 1431385.

In the brewing process xanthohumol is relatively instable and is mainlyprecipitated via the trub, the yeast, by filtration and stabilisationdue to its limited solubility. Besides, xanthohumol is isomerised toiso-xanthohumol which also has a positive effect, however, to quite alower extent compared to xanthohumol. With the conventional method lessthen 0.2 mg/l XN are reached in the final beer in most of the cases. Insome stout or porter type dark beers XN contents of up to 1.2 mg/l XNwere found (Walker et al., Brauwelt 2003). With a special brewing methodwhich applies late hopping and a fast cooling of the beer wort it ispossible to increase the XN content in non-filtered pale beers to 1-10mg/l (DE 102 56 166).

It is an advantage of the present invention that the isomerisation ofxanthohumol to iso-xanthohumol is suppressed to a large extent due tothe improvement of the brewing method. Therefore, it is possible toincrease dosage amounts of XN without allowing the beers to becomeunpleasantly bitter, for instance. Further, the addition of stabilisersis possible which would normally lead to a relevant decrease in the XNcontent.

A method for producing the roasted extract comprising XN from roastedproducts of cereals, cereal malt, coffee or cacao and a hop extractcomprising XN is an object of the present invention. The hop extractcomprising XN is characterised by a particularly high content ofxanthohumol. It is in the range from 10 mg to 2 g/kg, preferably in therange of 200 mg to 850 mg/kg. Due to the use of this roasted extractbeers with a significant increased content of XN compared to the priorart can be obtained in accordance with the German purity law, forinstance.

Herein, “roasted extract comprising XN” denotes an extract which isobtainable from a roasted extract from roasted products of cereals,cereal malt, coffee or cacao and from the hop extract comprising XN.“Roasted extract” denotes a cold or hot extract from coarsely ground ornon-ground roasted malt or cereals and includes a hot or cold extractfrom coffee or cacao; “cereal malt” denotes a cereal that wasartificially or controllably allowed to germinate, and “hop extractcomprising XN” denotes an extract from hops which was obtained with theaid of a solvent and exhibits an increased content of XN. “Basicmaterials” is a collective term for plain or combined substances whichmay be of natural or synthetic origin. They are used as parent materialfor the further production of food products. In the present inventionbasic materials denote e.g. essences which may be enriched with XN aswell as e.g. a basic material for coke according to an embodiment of thepresent invention.

For producing roasted extract comprising XN a hot aqueous extract of theground roasted products e.g. of barley, wheat, rye as well as thecorresponding malts, coffee beans or cacao beans is prepared. A hopextract comprising XN is added thereto at the beginning of the heatingperiod. The extraction of xanthohumol in the extractions of the roastedproducts leads to a XN content which is by far higher than thesolubility limit of XN in typical aqueous solutions. This amounts to 1.3mg/l of XN at a water temperature of 23° C. and to 1.1 mg/l of XN at awater temperature of 8° C.

Soluble roasted substances which adsorb or bind XN and therefore,apparently keep it in solution, are probably responsible for the highyields of xanthohumol in the extracts. The extracts may be fermented,concentrated or clarified without noteworthy losses of XN. According toone embodiment of the present invention a xanthohumol content ofapproximately 1320 mg/kg was obtained in the extract after concentrationof the XN comprising roasted malt wort.

The XN comprising roasted malt wort may be used in the food industrysuch as in the brewing and beverage industry as well as in the foodstuffindustry. Thus, the application of the XN comprising roasted malt wortmay lead to an enrichment of xanthohumol in spirits, herbal spirits,herbal liquor wine, beer, mixed drinks comprising beer, or bitters, andalso of non-alcoholic drinks or drinks with reduced alcohol content suchas malt beverages, coffee, coffee substitute, cacao, ice tea or softdrinks as well as of basic materials for the production of such productsin a simple, safe and economic way. A particular advantage is that aroasted malt beer enriched with XN and prepared according to this methodmay be added to a conventionally produced beer at any time of the beerproduction in accordance with the purity law, i.e., without the use ofemulsifying agents or other chemical additives.

An enrichment of food products with xanthohumol, such as bakeryproducts, backing kits, parfaits, dairy products (e.g. yoghurt, curdcheese and mixed drinks comprising milk) desserts, ice cream, meatproducts, sauces and herbal candies as well as enrichment ofpharmaceutical products with xanthohumol, such as cough syrup, is alsopossible.

The method for preparing an aqueous extract comprising XN from roastedproducts of cereals, cereal malt, coffee or cacao comprises thefollowing process steps:

-   -   a) addition of a hop product comprising XN to an extract which        is mainly or completely produced from roasted or colour malts,        respectively, or roasted barley; wherein the added hop product        has a content of XN which is, related to the mass used for its        production, at least 5 times that of the hops used for its        production; and wherein after the addition of the hop product        comprising xanthohumol to the aqueous roasted extract the        dissolving or even an intensive dissolving of XN is reached,        despite the original low solubility in aqueous solutions;    -   b) dissolving of XN by pre-dissolving of the XN comprising hop        product in ethanol;    -   c) dissolving of XN by agitating, mixing, shaking, supersonic        treatment, ultraturax treatment or other mechanical forces;    -   d) dissolving of XN by heating of the roasted extract;    -   e) dissolving of XN by application of an alternating current;    -   f) wherein the amount of the addition of the hop product        comprising XN is at least 50 mg XN per litre.

As will be understood from the following examples, it is not necessarythat all of the previously mentioned process steps are realised whenimplementing the process. The process steps b) to h) are optional.

In the following, examples of methods according to the present inventionand beverages produced thereby are given.

EXAMPLE 1

Preparation of beer wort from a mixture of special malt comprising 1.9kg of roasted barley malt (Carafa™, type 2, Fa. Weyermann, Bamberg) and0.1 kg of Pilsen type malt. After mashing according to the congressmethod and mash separation 25 g/l of a hop extract enriched with XN wereadded (XanthoExtrakt, Simon H. Steiner Hopfen GmbH, XN 2.0%) duringboiling of the roasted malt wort with the kettle-up wort concentrationof 11% w/w (weight/weight percent) and a wort colour of 1650 EBC(European Brewing Convention). After separation of hot trub and aseparation with diatomaceous earth the roasted malt wort comprising XNwas concentrated in vacuo (200 mbar, ca. 55° C.) to an extract contentof approximately 50% w/w. The syrup like extract (“density 1.25” kg/l)had a colour of approximately 7500 EBC and a content of xanthohumol ofapproximately 1320 mg/kg.

EXAMPLE 2

Preparing of beer wort from a special mixture comprising 0.05 kg ofPilsen type malt and 0.95 kg of roasted barley malt (Carafa™,Weyermann). After mashing according to the congress method and mashseparation the wort was boiled for 2 hours. At the start of boiling 5000mg/l of XN were added to the wort. For this, a hop extract comprising XNwith 80% of diatomaceous earth and 20% of hop extract (XanthoExtrakt,Hopsteiner, XN 1.7%) was used. Beside XN, this extract also comprisesα-acids and hard resins which have an influence on the flavour. The castwort having a concentration of 11.7% w/w was fermented within 2 days bybottom fermenting brewer's yeast and was centrifuged after 5 days ofstorage. The resulting roasted malt beer (RMB) had a colour of 1850 EBCand an XN content of 390 mg/l.

EXAMPLE 3

Method for preparing a roasted malt extract comprising XN according toexample 1, however, the wort was fermented with brewer's yeast,centrifuged and filtered with diatomaceous earth prior to concentration.The roasted malt beer thus prepared and having an original extract of12% and a colour of approximately 1700 EBC, had an XN content of 246mg/l.

EXAMPLE 4

Method for preparing a roasted malt beer comprising XN according toexample 3, however, the RMB was concentrated after the filtration invacuo (200 mbar, ca. 55° C.) to an extract content of approximately 48%.The density of the syrup like roasted malt beer comprising XN wasapproximately 1.2 kg/l, the colour was 6900 EBC, and the XN content was846 mg/kg.

EXAMPLE 5

Method for preparing a roasted malt extract comprising XN according toexample 1, however, an amount of approximately 100 mg XN per litre ofwort (11% w/w roasted malt extract) was dosed. Further treatmentaccording to examples 3 and 4 gave a roasted malt beer with an extractcontent of 47% w/w, a density of 1.2 kg/l, a colour of 7200 EBC and a XNcontent of 341 mg/l.

EXAMPLE 6

Preparation of a coffee extract from 40 g of ground roasted coffee and 1litre of hot water. After separation of the coffee grounds 100 mg of ahop extract comprising XN (XN content 80%) were added to the hot coffeeextract. The hop extract was intensively mixed at temperatures of above60° C. and it was further dissolved at 8° C. for 24 hours. Afterfiltration of the coffee beverage comprising XN using a fluted filterthe coffee beverage had an XN content of more than 12 mg/l.

EXAMPLE 7

Method for preparing a coffee beverage comprising XN according toexample 6, however, the filtered coffee beverage was dried in a freezedrier to a water content of less than 10%. The soluble coffee beveragecomprising XN had an XN content of 1042 mg/kg.

EXAMPLE 8

Approximately 1.8 g of the soluble coffee beverage comprising XNaccording to example 7 were mixed with 150 ml of hot water. The XNcontent of the mixed coffee beverage was approximately 10 mg/l.

EXAMPLE 9

To a non-filtered pale lager beer (XN content 0.1 mg/l) 2 g/l of theroasted malt beer comprising XN according to example 4 were added.Compared to the control beer a colour increase by 15 EBC and anenrichment of XN by 1.8 mg/l were detected in the bright beer.

EXAMPLE 10

To a non-filtered pale lager beer (XN content 0.1 mg/l) 20 g/l of theroasted malt beer comprising XN according to example 4 were added. Thefiltered beer had a colour of 120 EBC and a XN content of 13 mg/l.

EXAMPLE 11

To a filtered pale lager beer (XN content 0.05 mg/l) 20 g/l of theroasted malt beer comprising XN according to example 4 were added. Themixed filtered beer had a colour of 125 EBC and an XN content of 15mg/l.

EXAMPLE 12

To a typical basic material for coke consisting of two components, cokeessence, caramel colour and caffeine on the one hand, and phosphoricacid on the other hand, 880 g of a roasted malt beer comprising XNaccording to example 1 (concentration 1320 mg XN/kg) were added to 3.05kg basic coke material and homogenised. After mixing of the enrichedbasic material with processed water (3:1000), carbon dioxide (6.2 g/l)and sugar (110 g/l) a xanthohumol content of 1.1 mg/l was determined inthe ready-to-drink beverage.

EXAMPLE 13

To one kilogram of probiotic yogurt 2.29 g of roasted malt extractcomprising XN according to example 1 is added and homogenised. In thepasteurised product a xanthohumol content of 0.3 mg/100 g wasdetectable.

EXAMPLE 14

To a pharmaceutical product, here 1 litre of cough syrup, a roasted maltextract comprising XN (7.6 g) according to example 1 was added. Theresulting product comprised approximately 1.0 mg XN/100 ml.

1. Roasted Extract comprising xanthohumol (XN), obtainable from a roasted extract and a hop extract comprising XN.
 2. Roasted extract comprising XN according to claim 1, characterised in that the roast extract includes a cold or hot extract of coarsely ground or non-ground roasted malt, cereals, coffee or cacao.
 3. Roasted extract comprising XN according to claim 1 wherein the roasted XN extract has an XN content in the range of 10 mg/kg to 2 g/kg.
 4. Roasted extract comprising XN according to claim 3, characterised in that the roasted XN extract has an XN content in rage of 50 mg/kg to 1320 mg/kg.
 5. Pharmaceutical composition comprising the roasted extract comprising XN according to claim
 1. 6. Pharmaceutical product according to claim 5, characterised in that the pharmaceutical composition is a cough syrup.
 7. Food product comprising the roasted extract comprising XN according to claim
 1. 8. Food product according to claim 7, characterised in that the food product is a beverage.
 9. Food product according to claim 8, wherein the beverage is selected from the group consisting of spirits, herbal spirits, herbal liqueurs, bitters, wine, beer, or mixed beverages.
 10. Food product according to claim 8, wherein the beverage is selected from the group consisting of soft drinks, coffee beverages, coffee substitute, malt beverages, ice tea or basic materials for producing the same.
 11. Food product according to claim 7, wherein the food product is selected from the group consisting of bakery products, parfaits, dairy products, sweets, sauces and meat products.
 12. Food product according to claim 7, wherein the XN content is 10 mg/l to 400 mg/l.
 13. Method for producing a roasted extract comprising XN, wherein a hop extract comprising XN is mixed with a cold or hot extract selected from the group consisting of coarsely ground or non-ground roasted malt, cereals, coffee or cacao and which is concentrated thereafter.
 14. Method according to claim 13, wherein the added hop extract comprising XN has a content of XN which is in a range from 0.5 to 99% w/w of XN.
 15. Method according to claim 13, wherein the roasted extract comprising XN is concentrated to dry matter of 40-50% w/w (weight/weight percent).
 16. Method according to claim 15, wherein the concentrating is performed by evaporating, freeze drying or at reduced pressure.
 17. Method according to claim 13, wherein the roasted extract comprising XN is fermented by yeast and clarified.
 18. Method according to claim 17, wherein the clarifying is effected by a centrifuging or filtrating.
 19. Method according to claim 17, wherein the roasted malt beer enriched with XN is concentrated to an extract content of 40-50% w/w.
 20. Method according to claim 13, wherein the hop extract is pre-dissolved in ethanol for dissolving of the XN.
 21. Method according to claim 20, wherein the XN is dissolved by agitating, mixing, shaking, super sonic treatment and/or treatment with dispersing means.
 22. Method according to claim 20, characterised in that the dissolving of xanthohumol further includes heating and/or the application of an alternating current.
 23. Method for producing an aqueous extract comprising XN from roasted products of cereals, cereal malt, or coffee, characterised in that: a) the hop product comprising XN is added to an extract which is mainly or completely produced from roasted or colour malt, respectively, or roasted barley; b) the added hop product has an XN content which, related to its mass used for its production, is at least five times that of the hop used for its production; c) dissolving or even an intensive dissolving of XN is achieved after the addition of the hop product comprising XN to the aqueous roasted extract despite the originally low solvability in aqueous solutions; d) dissolving is promoted by pre-dissolving of the hop product comprising XN in ethanol; e) dissolving of XN is promoted by agitating, mixing, shaking, supersonic treatment, Ultraturax treatment or any other mechanical forces; f) dissolving of XN is promoted by heating of the roasted extract; g) dissolving of XN is promoted by applying an alternating current; h) the amount of addition of the hop product comprising XN is at least 50 mg of XN per litre.
 24. Method for producing the roasted extract comprising XN according to claim 23, further characterised in that the extract enriched with XN is concentrated to a dry matter of approximately 50%.
 25. Method for producing the roasted extract comprising XN according to claim 23, further characterised in that a) the extract enriched with XN is fermented by yeast, centrifuged or filtered; b) the roasted malt beer enriched with XN is concentrated to an extract content of e.g. 50%.
 26. Method for producing the extract comprising XN according to claim 23, further characterised in that a commercially available roasted malt extract and a commercially available roasted malt beer is used for dissolving the hop extract enriched with XN.
 27. Method for producing a roasted extract comprising XN according to claim 23, further characterised in that an extract from the commercially available roasted coffee and from the commercially available instant coffee is used for dissolving the hop extract enriched with XN.
 28. A method for enriching a beverage comprising adding roasted extract comprising xanthohumol with an XN content of more than 10 mg/kg which is produced according to claim 23 to a beverage.
 29. A method for producing a food product comprising adding roasted extract comprising xanthohumol with an XN content of more than 10 mg/kg which is produced according to claim 23 to a food.
 30. Roasted extract comprising xanthohumol with an XN content of more than 50 mg/kg which is produced according to claim
 23. 31. Roasted extract comprising xanthohumol with an XN content of more than 200 mg/kg which is produced according to claim
 23. 32. Roasted extract comprising xanthohumol with an XN content of more than 200 mg/kg. 